A geometric construction used in statics to resolve three or more coplanar forces. The force vectors are drawn head-to-tail in sequence. If the resulting shape is a closed polygon, the system is in equilibrium with no net force. If the shape is open, the line drawn from the start of the first vector to the end of the last represents the resultant force.
Heard on the job
The truss analysis is much easier if you sketch out the polygon of forces for that central node first.
Do not mix it up with
- Parallelogram of forces: The parallelogram resolves two forces, whereas the polygon resolves three or more.